The application of novel polypropylene to the insulation of electric power cable

The authors investigated the application of newly developed stereoregular syndiotactic polypropylene (s-PP) which was synthesized with homogeneous metallocene catalyst to the insulation of electric power cable. The electrical and thermal characteristics of s-PP are revealed to be superior to these of cross-linked polyethylene (XLPE) which has been adopted as conventional insulating material for high voltage power cable. Furthermore, s-PP is suitable for recycle use as the recent environmental requirement, because it is available without cross-linking in contrast with XLPE. To apply s-PP to practical cable insulation, its low temperature brittleness and thermal durability were improved. Consequently, the 600V and 22kV class cables with thus improved s-PP insulation were successfully manufactured first in the world. The results of some electrical tests on these cables indicated that s-PP could be available to the insulation of power cable.